#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
using namespace std;

const int N = 1e6 + 10, INF = 0x3f3f3f3f;

int n;
int cnt[26];
string s;

void solve()
{
    memset(cnt, 0, sizeof cnt);
    cin >> n >> s;
    for (int i = 0;i < n;i++)
        cnt[s[i] - 'a']++;

    for (int i = 1;i < n - 1;i++)
        if (cnt[s[i] - 'a'] >= 2) { cout << "Yes\n"; return; }

    cout << "No\n";
}

signed main()
{
    // ios::sync_with_stdio(0);
    // cin.tie(0);cout.tie(0);
    // #define ONLINE_JUDGE
#ifndef ONLINE_JUDGE
    std::istringstream in(R"(12
3
aaa
3
aba
3
aab
4
abca
4
abba
4
aabb
5
abaca
5
abcda
5
abcba
6
abcbbf
6
abcdaa
3
abb
)");
    std::cin.rdbuf(in.rdbuf());
#endif
    int T = 1;
    cin >> T;
    for (int i = 1;i <= T;i++) {
        solve();
    }
}